title: Phytochemical study and screening for antimicrobial activity of flavonoids of Euphorbia hirta.
abstract: OBJECTIVE
  This study aims to phytochemical and antimicrobial study of Euphorbia hirta Euphorbiaceae).
  
  
  METHODS
  Antimicrobial activity of flavonoids (free and bound) of Euphorbia hirta L. was determined by disc diffusion assay against four bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus) and four fungi (Aspergillus flavus, Aspergillus niger, Trichophyton mentagrophytes, and Candida albicans). Minimum inhibitory concentration (MIC) of the extract was evaluated through micro broth dilution method, while minimum bactericidal/fungicidal concentration was determined by subculturing the relevant samples. Total activity (TA) of extracts against each sensitive pathogen was also evaluated.
  
  
  RESULTS
  Out of fungi; A. flavus, A. niger, and T. mentagrophytes were found to be resistant, against which none of the tested extracts showed activity. Bound flavonoids extract of root showed best activity against C. albicans (inhibition zone (IZ) 27.66, MIC 0.039, minimum fungicidal concentration (MFC) 0.039). TA of free flavonoid extract of root was found to be the same for P. mirabilis and S. aureus (192.30 ml/g). Two flavonoids quercetin and kaempferol were identified in the bound flavonoids of stem extract which showed activity against all the microorganisms.
  
  
  CONCLUSIONS
  Results of the present investigation indicate that E. hirta has good antimicrobial activity with low range of MIC, hence can be exploited for future plant-based antimicrobial drugs.
authors.affiliation: Department of Botany, Laboratory of Plant Tissue Culture and Secondary Metabolites, University of Rajasthan, Jaipur, Rajasthan, India.
authors.forename: Geeta
authors.initials: G
authors.lastname: Singh
authors.forename: Padma
authors.initials: P
authors.lastname: Kumar
keywords: Euphorbia hirta; flavonoid; kaempferol; minimum inhibitory concentration; quercetin; total activity